There are a few ways I like to extend my battery life on my MacBook Air. These days, it’s increasingly important to conserve battery life as the transition to Mountain Lion (Mac OS X 10.8) has caused my battery life to spiral into so much of a vortex that I am concerned that my laptop must be shooting raw electricity out of the bottom (which would certainly explain why my hair has a tendency to be perpendicular with the ground when I exit a plane). Ever since moving to Mountain Lion (yes, this includes 10.8.2), I’m lucky to get 3 hours of battery life out of the Mac that used to give me at least 5 hours…
There are a number of tricks that I use to extend battery life. Some are obvious, such as dimming the screen, only using an app at a time, killing off menu items, temporarily stop Spotlight Indexing and killing off LaunchDaemons and LaunchAgents that I’m not using. I even used to used an app called CoolBookController to throttle my processor speeds while flying. But that doesn’t work as of Lion (certainly not in Mountain Lion).
One thing that I’ve been able to do that extends my battery life a little more (maybe an extra half hour) is to kill off Notification Center (I wrote about customizing Notification Center earlier here). I know, I know, it shouldn’t matter… But recently, a customer asked me to script disabling Notification Center. Since I’ve been killing it off with a script, this was a pretty straight forward task. It’s easy to disable Notification Center temporarily using the GUI. Simply click on the Notification Center icon in the menu bar and then scroll up to see the “Show Alerts and Banners” button. Click OFF or ON to toggle it off and on. As you can see, Notification Center then starts back up the next day.
To disable Notification Center from the command line, write a KeepAlive key that is false into the /System/Library/LaunchAgents/com.apple.notificationcenterui.plist like so:
sudo defaults write /System/Library/LaunchAgents/com.apple.notificationcenterui KeepAlive -bool false
Then, if you kill NotificationCenter off, it’ll stay off:
killall NotificationCenter
If you want to re-enable Notification Center, you’d just run the same with a true:
sudo defaults write /System/Library/LaunchAgents/com.apple.notificationcenterui KeepAlive -bool true
The easy way to then get it back is to reboot. Now, just for giggles, Notification Center is actually the /System/Library/CoreServices/NotificationCenter.app and in there lies the /System/Library/CoreServices/NotificationCenter.app/Contents/MacOS/NotificationCenter binary. If you open it, you’ll get multiple Notification Center icons in the menu bar. I’m not sure why I decided to try that at some point. But it’s kinda’ fun…
Ultimately, I travel with multiple MacBooks, so rather than toss one of them in a checked bag, or one destined for the overhead, I am temporarily just keeping a second 11 in the bag I keep under the seat in front of me for now…